CHEMICAL BONDING 9 (d) One of the carbons in propene is sp-hybridized. The carbons of the double bond are sp-hybridized H3C-CH=CH2 (e) The carbons of the CH, groups in acetone [(CH,),C-O] are sp-hybridized. The C-O carbon is sp--hybridized. (f) The carbons in acrylonitrile are hybridized as shown: H,C=CH—C≡N 1.23 All these species are characterized by the formula: X=Y:, and each atom has an electron count of 5 X≡Y Unshared electron pair contributes 2 electrons contributes 2 electron to electron count of X to electron count of y Triple bond contributes half of its 6 electrons or 3 electrons each ts of x and y Electron count X= electron countY=2+3=5 (a) :NEN: A neutral nitrogen atom has 5 valence electrons: therefore, each atom is electri- cally neutral in molecular nitrogen. Nitrogen, as before, is electrically neutral. A neutral carbon has 4 valence electrons, and so carbon in this species, with an electron count of 5, has a unit negative charge. The species is cyanide anion; its net charge is -1 (c):C There are two negatively charged carbon atoms in this species. It is a dianion; its net charge is-2. (d) :N=O: Here again is a species with a neutral nitrogen atom. Oxygen, with an electron count of 5, has I less electron in its valence shell than a neutral oxygen atom. Oxygen has a formal charge of +1; the net charge is +1 (e) :C=O: Carbon has a formal charge of -1; oxygen has a formal charge of +1. Carbon monoxide is a neutral molecule 1.24 All these species are of the type Y=X=Y: Atom X has an electron count of 4, corresponding to half of the 8 shared electrons in its four covalent bonds each atom y has an electron count of 6 4 unshared electrons plus half of the 4 electrons in the double bond of each Y to X (a):O=C= Oxygen, with an electron count of 6, and carbon, with an electron count of 4 both correspond to the respective neutral atoms in the number of electrons they"own. Carbon dioxide is a neutral molecule, and neither carbon nor oxygen has a formal charge in this Lewis structure (b) :N=N=N: The two terminal nitrogens each have an electron count(6)that is one more than a neutral atom and thus each has a formal charge of -1. The central N has an electron count (4 )that is one less than a neutral nitrogen; it has a for mal charge of +1. The net charge on the species is As in part(b), the central nitrogen has a formal charge of +1. As in part(a), each oxygen is electrically neutral. The net charge is +1 123mBm打mpmm门 nt ho tona nd alumi s me re grau ne Back Forward Main Menu TOC Study Guide Toc Student OLC MHHE WebsiteCHEMICAL BONDING 9 (d) One of the carbons in propene is sp3 -hybridized. The carbons of the double bond are sp2 -hybridized. (e) The carbons of the CH3 groups in acetone [(CH3)2C?O] are sp3 -hybridized. The C?O carbon is sp2 -hybridized. ( f ) The carbons in acrylonitrile are hybridized as shown: 1.23 All these species are characterized by the formula • •X>Y• •, and each atom has an electron count of 5. Electron count X electron count Y 2 3 5 (a) A neutral nitrogen atom has 5 valence electrons: therefore, each atom is electri￾cally neutral in molecular nitrogen. (b) Nitrogen, as before, is electrically neutral. A neutral carbon has 4 valence electrons, and so carbon in this species, with an electron count of 5, has a unit negative charge. The species is cyanide anion; its net charge is 1. (c) There are two negatively charged carbon atoms in this species. It is a dianion; its net charge is 2. (d) Here again is a species with a neutral nitrogen atom. Oxygen, with an electron count of 5, has 1 less electron in its valence shell than a neutral oxygen atom. Oxygen has a formal charge of 1; the net charge is 1. (e) Carbon has a formal charge of 1; oxygen has a formal charge of 1. Carbon monoxide is a neutral molecule. 1.24 All these species are of the type • •Y • • ?X?Y • •• •. Atom X has an electron count of 4, corresponding to half of the 8 shared electrons in its four covalent bonds. Each atom Y has an electron count of 6; 4 unshared electrons plus half of the 4 electrons in the double bond of each Y to X. (a) Oxygen, with an electron count of 6, and carbon, with an electron count of 4, both correspond to the respective neutral atoms in the number of electrons they “own.” Carbon dioxide is a neutral molecule, and neither carbon nor oxygen has a formal charge in this Lewis structure. (b) The two terminal nitrogens each have an electron count (6) that is one more than a neutral atom and thus each has a formal charge of 1. The central N has an electron count (4) that is one less than a neutral nitrogen; it has a for￾mal charge of 1. The net charge on the species is (1 1  1), or 1. (c) As in part (b), the central nitrogen has a formal charge of 1. As in part (a), each oxygen is electrically neutral. The net charge is 1. 1.25 (a, b) The problem specifies that ionic bonding is present and that the anion is tetrahedral. The cations are the group I metals Na and Li. Both boron and aluminum are group III O N O N N N O C O C O N O C C C N N N Unshared electron pair contributes 2 electrons to electron count of X. Unshared electron pair contributes 2 electrons to electron count of Y. Triple bond contributes half of its 6 electrons, or 3 electrons each, to separate electron counts of X and Y. X Y H2C CH C N sp2 sp2 sp H3C CH CH2 sp3 sp2 sp2 Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website